Basic data transfer systems for transmitting information between a pulling vehicle and a trailer are known. Typically, these systems include data collectors at the rear of the vehicle and a notification device in view of a driver in the cab. The data collection mechanisms typically include various sensors for interacting with the notification device. Signals generated by the sensors are then capable of notifying the driver of a situation behind the vehicle. The sensors may typically include radar mechanisms, cameras, ultrasonic and infrared sensors, which signal the notification device in order to notify the driver about various conditions in and around the vehicle cab and trailer. For example, in the case of the camera, the signal generated by the camera is transmitted to a display screen included in the notification device or, in the case of the radar mechanism, to an acoustic warning device in the cab. Using such a system, the driver of a large tractor trailer can be assisted when backing up, such as in parking, and can avoid a collision with any obstacle, such as a parked vehicle.
With such a data transfer system as described above, a connection between the notification device in the tractor and the data collector in the trailer is established by wires running through the vehicle. However, a problem arises in that a connection must be provided between the notification device and the data collector that can be disconnected, enabling the trailer to be unhooked or traded to a different pulling vehicle.
Attempting to avoid the above noted problem, German utility patent 201 10 339.7 describes a parking assistance system in which data about obstacles behind the vehicle is collected by sensor and broadcast via radio communication to the notification device near the driver, thereby facilitating simpler hitching and unhitching by eliminating the connection of wires between the tractor and trailer.
However, there are several new problems that arise with this system. In the case of a commercial sized tractor-trailer, the transmission path necessary to transfer the data from the data collector in the rear of the trailer to the notification device in the cab is relatively large, requiring a relatively strong radio signal. This strong radio signal can then disturb similar equipment that is insufficiently shielded. Accordingly, a trucking company that operates several trucks with this equipment must pay special attention that the equipment in a specific tractor-trailer communicates only with itself and does not interfere with the equipment of another tractor-trailer in the fleet. For this reason, the system must have a distinct identifier and it must be secured, such as by encoding the signals, so that the respective transmitting device only communicates with the corresponding receiver in the same truck. Thus, each pair of transmitters and receivers requires specific codes or protocols that are either programmed in advance or are “defined” at transmission. This increases the complexity of these devices and diminishes the data transfer rate that is utilizable in the transfer of images or other sensor information because a part of the data transfer has to be used for the required encoding overhead.
Additionally, as a matter of some logistics, it is preferable in a modern fleet of trucks to at any time provide other information concerning the trailer being towed, such as data about the load, temperature in a refrigeration unit, the destination, and the maintenance of the trailer, as opposed to just a picture of the lane behind the trailer.
Accordingly, it is an object of the present invention to provide a data transfer system for use in a tractor-trailer in which a variety of data can be wirelessly transferred from sensors in the trailer across the hitching space to a notification device in the tractor, which can assist the driver in operation of the vehicle.
It is another object of the present invention to position the wireless transmission devices as closely as possible to each other across the hitching space to simplify data transmission and reduce signal strength to enable only a minor overhead of protocol data for increased transmission rate with reduced interference to other similar systems.